This mini-game is played in Macalania Woods. Speak to the creature with the harp for details on how to play. Touch a butterfly to begin the game. After gaining access to the airship, winning the mini-game will get you Kimahri's Sigil.

Chocobo racing is located at Remiem Temple. Just outside you can race against the Champion Chocobo.

To start the chocobo race you need to go up to the champion chocobo on the right hand side of the temple and challenge it. You will then start the race. The aim is to get to the middle before the other chocobo gets their getting as many treasure chests as possible. The more treasure chests you open the better the prizes you get are. You must also avoid hitting any of the poles or you lose the race.

Click on the map below to view a larger version of the chocobo racing area. The lines shows the recommended route.

The Monster Arena is located on the eastern edge of the Calm Lands. There you can purchase equipment that allows you to capture fiends. Capturing certain fiends will get you a special prize from the trainer. You can also fight special creations (that are more challenging than a regular fiend) for valuable prizes.

To find Remiem Temple, rent a chocobo in the Calm Lands and ride up towards the southern exit. Continue to the right and you will see a chocobo feather on the ground. Examine it to fly toward the other side. Follow the path to Remiem Temple. Inside you will find Belgemine ready to have an aeon duel with Yuna. You must obtain all aeons (except the Magus Sisters). Each time you defeat one of her aeons, she will give you a prize. For defeating her Bahamut, you will get the Flower Scepter.

See the side quest "Magus Sisters" for more information on obtaining the trio. After obtaining the aeon trio, you can defeat all of Belgemine's aeons. She will give you Yuna's Moon Sigil before asking you to send her.

To find the secret locations, you must first have the airship. On the world map, search the coordinates by moving the cursor over the map. Press the X button to search for the location. You'll notice that the coordinates have a range that can be searched.

When you've acquired control of the airship, you can enter passwords to find other secret locations. Choose the "Input" command to bring up the screen's keyboard. The passwords must all be entered in all capital letters. You may have seen these passwords translated into Al Bhed hints around Spira.

Password 1: GODHAND

You'll have access to the ravine below Mushroom Rock Road. Continue north and you'll come across a chest that contains Rikku's ultimate weapon, Godhand.

Password 2: VICTORIOUS

You'll have access to another secret area in Besaid. Climb up the tree branch and open the chest there to find Victorious, a targe for Rikku that nullifies three elements.

Password 3: MURASAME

You'll have access to another secret area in Besaid. Go to the north to find a chest that contains Murasame, a sword for Auron that has the One MP Cost ability.

To obtain the Magus Sisters, you must first defeat all of Belgemine's aeons at Remiem Temple. You will receive the key item Flower Scepter for defeating her Bahamut. You must capture all of the fiends of Mt. Gagazet (see Monster Arena (FFX)). When you return to the owner of the Monster Arena, he will reward you with the key item Blossom Crown. Using both of these items, return to Remiem Temple and examine the door in the back.

There are many tricks with which you can get AP quickly and effectively, below are two methods which work the best.
To find out where to get the items please read the Item FAQ ([1]) by AZn2th3N.
To do these methods you should have the following:

Phoenix Downs - Although they may not actually be necessary as life can work just as well, its best to have as many Phoenix downs as possible

Misc

Don Tonberry unlocked - One of area conquest creatures found in the Monster Arena (requires you captures all fiends in the Cavern of Stolen Fayth)
Cactuar King unlocked - One of area conquest creatures found in the Monster Arena (requires you captures all fiends in the Thunder Plains)
1000+ Kills - this is needed for the Don Tonberry method, however it is not essential

You must have unlocked one or the other for the tricks to work.

DON TONBERRY METHOD

Select to fight against the Don Tonberry, and then attack it. This will result in it retaliating with Karma which will deal damage depending on how many fiends that character had killed x100. If you have set the overdrive mode to Comrade then two characters will gain AP for the attack as instead of your overdrive gauges charging you will gain AP. After the attack revive the fallen character and then repeat until the hearts desire or until it is defeated (or you run out of Phoenix Downs)
Please note for this method you MUST have Overdrive-->AP ability and it is highly recommended that you have Auto-Phoenix and a huge supply of Phoenix Downs. Its also better to use Comrade mode on the characters with less Kills and stoic on the one with the most kills. However if all your characters have fairly high amount of kills its a good idea to use Comrade for all characters.
After you finish you will gain an absurd amount of AP.

CACTUAR KING METHOD

Select to fight against the Cactuar King, and then attack it. It will then retaliate with either 10,000 Needles or 99,999 Needles. Revive your characters when needed and keep attacking. When it attacks it will attack with either one of the two moves resulting in even more AP. Remember to have set the overdrive mode to Comrade for all your characters.
Please note for this method you MUST have Overdrive-->AP ability and it is highly recommended that you have Auto-Phoenix and a huge supply of Phoenix Downs. Life will also do just as well, however it will waste a turn.
Again after you finish you will gain an absurd amount of AP.